Fig. 2.

Experimental evolution of switching. a Sequence of events during one experimental cycle: (1) 2 days of asexual growth to saturation. (2) Transfer of 1% of the cells to a nitrogen-deficient medium. (3) Killing of non-mated haploid and unsporulated diploid cells with enzyme treatment and ethanol. (4) Transfer of sexual spores to a fresh medium for asexual growth. b Mating-type configuration of parental strains used in the experiment (top) with non-switching phenotype (h^–S and h^+S), and configuration of the long-read sequenced-evolved switching strain (EBC7; bottom) with an active mat1 locus indicated by the red box. The evolved strain contains an additional mating-type cassette, which allows the strain to switch between P and M